Maths Mate sheet 8 term 1

Question

A gambler begins with $21. In the first minute he loses $5, the next minute he wins $3. How long does he take to lose his $21 if he continues losing and winning in this way.

Predict

I predict that in this question I will have to use addition and subtraction.

Strategy

draw a diagram

 

Working  Out

I used a diagram to work out this problem. First I drew a line then at the top  of the line I wrote 21 and at the bottom of the line I wrote 0, then I went through the process of the addition and subbtraction. first taking away 5 then adding 3 until I got to 0 at the bottom of the line.Then I counted all of the 3’s and 5’s to get my answer

21

21-5=16

16+3=19

19-5=14

14+3=17

17-5=12

12+3=15

15-5=10

10+3=13

13-5=8

8+3=11

11-5=6

6+3=9

9-5=4

4+3=7

7-5=2

2+3=5

5-5=0

0

 

Answer:17

Can you see the pattern?